This was the best selling third party game for Switch in Japan for 2018.

The sales listed are retail, we don't know eShop sales data so it could be closer to a million.

This is from Microsoft so it is currently their best selling game in Japan on consoles ever.

The best selling third party game for Switch in 2018 is from a western studio.

Yes, Switch got three 2 million sellers in 2018: Splatoon 2, Smash Bros. Ultimate and Mario Kart 8 Deluxe but, when you hear that Nintendo's best third party support in Japan is from Microsoft, that makes you wonder about the rest of the third party support for Switch in Japan.

It’s definite correct to add Steve, but it’s definitely incorrect to not add BK first, which has me wonder whether they’re going to save MS for the final dlc pack and do a surprise secret two in one where you get Banjo Kazooie and Steve together*

*Though it should be three in one as Joanna Dark REALLY should be there too.

it was not made by microsoft for starters(they dont have internal big games for younger demographics), also is a game suited for kids (nintendo hardware), but microsoft does have the means to support and promote the game in ways that indie developers cant. Its also not a shooter or western focused game, its for everyone, everywhere, therefore also a hit in japan

Pretty sure it's by far the best-selling Vita game too in Japan. First and third party. It probably outsold the top 5 Sony first party games for the Vita in Japan. Or rather the 5 behind it since I think Sony published it there.